Cocoa have been known for a long time for its stimulating and lipolytic characteristics due to the presence of pseudoalcaloids belonging to the methylxanthine family such as theobromine, caffeine and theophylin, having the following structural formulas:

Pseudoalcaloids belonging to the methylxanthine family are known for their action on the inhibition of phosphodiesterase enzymes (PDE) of cyclic nucleotides, resulting in an increase in the concentration of intracellular AMPc (cyclic adesosine 3′,5′ phosphate) and cyclic GMP, promoting lypolisis in adipocytes. Besides that mechanism, there is also an antagonism in adenosine receptors which, when activated, promote a reduction in the accumulation of AMPc, therefore impairing lypolisis (Fredholm, B. & Lindgren E.; 1984), as well as stimulation of β-adrenergic receptors. Due to the stimulating and lypolitic characteristics of methylxantines, its use in cosmetics products for treating and preventing localized fat and celullite has been largely spread.
A number of processes for extracting methylxantines from cocoa have been described in the literature. However, the processes already disclosed in the art do not show a high yield in obtaining methylxanthines and are, in the most part, highly energy expensive and time-consuming, and besides they focus on caffeine rather than theobromine extraction, the latter usually present in concentrations smaller than caffeine in the end products obtained. This is partially due to the physical-chemical differences between caffeine and theobromine. Caffeine behaves as a weak base (pKa=14.2) and, therefore, able to solubilize in water at an acid pH and in apolar solvents at a basic pH. Theobromine, unlike caffeine, has an amphoteric behavior (pKa=10.0 and pKb=13.9) (Spiller, G. A.; 1998). Thus, theobromine is solubilized in water at extreme pHs, or too acid or too basic. Its solubilization in apolar solvents occurs in a very narrow range of pH. Thus, for concurrently extracting caffeine and theobromine in apolar solvents such as dichloromethane, a very strict control of pH in a determined range of pH is necessary.
The following documents represent the state of the art closest to the present invention. All of them relate to a process of obtaining methylxanthines from materials derived from cocoa and/or compositions containing cocoa derivatives.
U.S. Pat. No. 1,073,441: discloses a process for extracting methylxanthines by using chloroform as a solvent.
U.S. Pat. No. 1,855,026: discloses a process for extracting methylxanthines by using ethylene dichloride as a solvent.
U.S. Pat. No. 1,925,326: discloses a process for extracting methylxanthines by using tetrachloroethane as a solvent.
U.S. Pat. No. 4,755,391: this reference refers to a process for the treatment of cocoa grains and cocoa “nib” for removing methylxanthines. The process includes the aqueous extraction at between about 45° C. to about 55° C., then a series of steps of aqueous extraction at between about 90° C. to about 105° C. The use of a first aqueous extraction at low temperatures, followed by a series of steps of aqueous extraction at high temperatures, results in a greater amount of extracted theobromine.
US 2003/0170199 A1: this reference discloses a cosmetic composition containing an extract obtained from cocoa grains containing polyphenols for use for treating the skin. The extraction process used in this reference is a well-known process for grinding cocoa grains followed by hydrophylic/lypophylic separation of cocoa butter and a mixture of proteins and polyphenols.
WO 2004/103334 A1: this reference discloses a cosmetic or dermatologic composition comprising cafestol, kahweol or derivatives thereof, obtained from the extract of green coffee seeds and, optionally, a lypolithic agent as a synthetic xanthine base (caffeine or theobromine), for preventing and/or treating celullite.
Methylxanthines act as fosfodiesterase inhibitors, bringing about accumulation of intracelullar AMPc, thus establishing a signal for the increase of lypolithic activity in adipocytes. There has been shown in an ex vivo model study with adipocytes that caffeine and theobromine have equivalent power on noradrenaline-induced lypolisis. Lypolisis rate has been measured by the increase of intracelullar glycerol (Fredholm, B. & Lindgren E.; 1984). Those same researchers have demonstrated in the same work that theobromine is 50% more powerful, than caffeine in antagonizing the anti-lypolithic effects of 2-chloroadenosine, mediated by adenosine receptors. In a study of in vitro bovine fosfodiesterase inhibitors, the power of theobromine and caffeine in the ability of increasing AMPc have also be identical (Butcher, R. E & Sutherland, E. W.; 1962). Those information indicate the use of caffeine and theobromine as promising substances for the treatment of celullite in humans, at first by two distinct mechanisms, both by promoting accumulation of AMPc and inhibiting adenosine receptors.